# OAR Box 1870

Prepped by Ollie Stewart



## Document

Number: 

# 25 ) ll-A-2 8
Docket Number: 

# A-90-1 9

Printed 11/28/20087:05:04 AM Sheet 25of 67 P. 1

## P. 2

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### Destructio n o f

Ai r Emission s Usin g Catalyti c Oxidatio n 

# Kn-fk'CWXy A-90-1 9 ll-A-2 8

PP8R-? 1 J'» c ' '



### (U.S. ) Environmenta l Protectio nAgenc y Researc hTriangl e Park , N C

Ma y8 8



# [ ]

U.S
. Departmen t of Commerc e National'Technica l 'nformatio n Servic e 

# Radia n LibraryP. 3

Pddo- i 1 «**:>< :

EPA/600/D-8P/10 7 Ma y 198 8

DESTRUCTIO

N O F AI REMISSION S USIN G CATALYTI

C OXIDATIO

N

o y

Michae l Kosusk o an d Gedde s Ramse y Ai r an d Energ yEngineerin g Researc h Laboraror y U.S
. Environmenta l Protectio n Agenc y Researc h Triangl e Park , N C 2771 1

EP AProjec t Office r .-lichae l Kosusk o

AI R AN D ENERG Y ENGINEERIN G RESEARC H LABORATOR Y OFFIC E O F RESEARC H AN D DEVELOPMEN T U.S
. ENVIRONMENTA L PROTECTIO NAGENC Y RESEARC H TRIANGL E PARK , N C 2771 1

REPRODUCE D B

Y U.S
. DEPARTMEN TO F COMMERC E Nationa l Technica l Informatio n Servic e SPRINGFIELD , VA
. 2216 1P. 4 

# .££x2.<0±fX. SA C

TECHNICA L REPOR TDAT A (Htast rttd lauruetiont

o n thi

rtvtnt btfort completing' 1
. REPOR TNO
. EPA/600/D-88/10 7 4
. TITL E AN O SUBTITL E 6
. REPOR TDAT S 

### Destructio n o

f /i r Emission s Usin g Catalyti c Oxidatioq__Ma^_i988

_ I
. PSRPORMIN O OROANIZATiO N COO E

I
. PERFORMIN G OROANI2ATIO N NAM E AN O AOORES S 7
. AUTHORS ) 

### Michae l Kosusk o an dGedde s M

. Ramse y f
. PSRPORMIN O ORGANIZATIO N REPOR TN O

II


### Se e Bloc k

1 2

12
. SPONSORIN G AGENC Y NAM C AN O AOORES S 

### EPA , Offic e o

f Researc hand Developmen t Ai r an dEnerg y Engineerin g Researc hLaborator y Researc hTriangl e Park , N C 2771 1 

# x

# mw:Ti ESSiQ * NO : 

## /A

S

10
. PRGORA M ELEMEN TNO
. 

### rrrsfjrirxerTswiumu: N A

13
. TYP E O P REPOR TAN O PERIO O COVERE D 

### Publishe dpape r 14
. SPONSORIN G AGENC Y coo i 

### EPA/600/1 3 ^.SUPPLEMENTAR Y NOTE S A £ER L projec t office r i s Michae l Kososko
. Mai l Dro p 61
. 919 / 541-2734
. 

### is

. AS S »A C j^ e 

### pape r

discusse s ke y emissio n strea mcharacteristic s an dh ; zardou s ai r pollutan t

(HAP ) characteristic s tha t affec t th e applicabilit y o

f catalyti c oxidatio n a s a n ai r pollutio n contro l techniqu e i n whic hvolatil e organi c compound s (VOCs ) an d vapor-phas e ai r

toxic s i n a n ai r

emissio n strea mar e oxidize dwithth e hel p o f acat

alyst

. Desig n o

f catalyti c system s fo r

contro l o

f poin t sourc e emission s i s base don stream-specifi c characteristic s an ddesire dcontro l efficiency

. Th e applicatio n o f catalyti c oxidatio n t o fou r type s o f ai r emissio n source s i s discussed : groundwate r strippin g operations , graphic s art s (heatse t printing ) facilities , flexographi c prin

tin g plants , an dlate x monome r production

. Th e characteristic s o f eac hemissio n ar e discusse dalon g withth e catalyti c technolog y use dt o contro l it

. I n addition , severa l catalyti c system s ar e identifie dfo r contro l o

f ai r emissions , alon g withinformatio n abou t thei r technolog y an dthei r

positio n i n th e marke t place

. Finally , som e roug h economic s ar e presente dwhic hcompar e catalyti c oxidation , carbo n adsorption , an d therma l incineratio n systems

.

KE Y WORD S AN O DOCUMEN T ANALYSI S DESCRIPTOR S 

### Pollutio n Groun dWate r Incinerator s Strippin g Catalysi s Graphi c Art s Organi c Compound s Volatilit y Flexograph y Toxicit y Late x

Activate dCarbo n 19
. DISTRIBUTIO N STATEMEN T 

## Releas e t o Publi c b.lOENTIPISRS/OPE N (NOE O TERM S 

### Pollutio n Contro l Stationar y Source s Catalyti c Oxidatio n Groundwate r

Strippin g Heatse t Printin g

19
. SECURIT Y CLAS S (ThURtport) 

### Unclassifie d 2 0 SECURIT Y CLAS S (ThUpf) 

### Unclassifie d c . COSAT I Field/Grou p 

### 13 B 07 D 0 7 C 20 M 06 T 08 H 07A.13 H 14E.05 F

11J 11G 2 1
. NO
. O P PAGE S 2 8 22
. PRIC E PG}j 13
. q C ( P A Per m JJ10- I <t-71 )/ ' • P. 5

NOTIC E Thi s documen t ha s bee nreviewe d inaccordanc e wit h U.S . Environmenta l ProtectionAgenc y polic y an d approve d fo r publication . Mentio no f trad e name s o r commercia l product s doe s no t constitut e endorse men t o r recommendatio nfo r use .

1 1P. 6

DESTRUCTIO N

O F AI REMISSION S USIN GCATALYTI C OXIDATIO N



### b y

Michae l Kosusk o an

dGedde s Ramse y U . S . Environmenta l Protectio nAgenc y Ai r S Energ y

Engineerin g Researc hLaborator y A1 r Toxic s Contro l Branc h Researc hTriangl o Park , Nort hCarolin a 2771 1

ABSTRAC T
Catalyti c Incineratio ns a nai r pollutio ncontrol , techniqu e 1 n whic hvolatil e organi c compound s (VOCs ) andvapor-phas e ai r toxic s 1 na n ai r emissio nstream ar e oxidize dwit hth e hel po f a catalyst . Desig no f catalyti c system s fo r contro l o f poin t sourc e emission s I s base do n stream-specifi c characteristic s an ddesire dcontro l efficiency . Thi s pape r discusse s th e key emissio nstream

characteristic s an dhazardou s ai r pollutan t (HAP ) characteristic s tha t affec t th e applicabilit y o f catalyti c oxidation . Th e applicatio no f catalyti c oxidatio ntechnolog y t o fou r typo s o f ai r emissio nsource s i s discussed . Thes e are : (1 ) groundwate r strippin g operations ; (2 ) graphi c art s facilities ; (J ) flexographi c printin g plants ; an d(4 ) late xmonome r production . Th e characteristic s o f eac ho f thes e emission s ar e discusse dalon g wit hth e catalyti c technolog y use dt o con tro l thes e emissions . Inaddition , severa l catalyti c system s fo r contro l o f ai r amission s ar e identifie dalon g wit hInformatio nabou t thei r technolog y andthei r positio ni nth e marke t place . Finally , som e roug heconomic s ar e pre sente dwhic hcompar e catalyti c oxidation , carbo nadsorption , andtherma l Incineratio nsystems .P. 7

INTRODUCTIO N

Th e mos t frequen t approac ht o poin t sourc e ai r emission s contro l 1 s th e applicatio no f add-o ncontro l devices . Fo r organi c vapors , thes e device s ca n be o f tw o types : combustio nan d recovery . Applicabl e combustio ndevice s ar e therma l Incinerators , catalyti c incinerators , flares , an d boilers/proces s heaters . Applicabl e recover y device s includ e condensers , adsorbers , an d absorbers . Th e combustio ndevice s ar e th e mor e commonl y applie d contro l devices , sinc e the y ar e capabl e o f highremova l (I.e. , destruction ) efficien cie s fo r almos t an y typ e o f hazardou s ai r pollutan t (HAP) . Th e remova l efficiencie s o f th e recover y technique s generall y depen d onth e physica l and chemica l characteristic s o f th e HA P unde r consideration . Applicabilit y

o f th e contro l technique s depend s mor e o nth e individua l emissio nstrea

m unde r consideratio ntha no nth e particula r sourc e categor y (e.g. , degreasin g vs . surfac e coatin g i nth e solven t usag e operation s sourc e category) . Thus , applicabl e contro l technique s fo r poin t sourc e emission s ar e selecte d o nth e basi s o f stream-specifi c characteristic s and desire d contro l efficiency . Th e key emissio nstrea

m characteristic s an d HA P charac teristic s tha t affec t th e applicabilit y o f eac hcontro l techniqu e are : HAP / organic s content , hea t content , moistur e content , flo w rate , temperature , an d molecula r weight . Matchin g th e characteristic s o f th e stream unde r consideratio nwit hth e usefu l '-anges o f th e contro l device s wil l hel p th e use r t o identif y thos e technique s tha t ca npotentiall y b e use d t o contro l th e emissio nstream . Catalyti c oxidation , fo r example , 1 s generall y usefu l fo r concentration s o f 5 0 t o 10,00 0 ppmv , i f th e tota l concentratio n1 s les s tha n25 % o f th e lowe r explosiv e limi t (LEL) , and fo r flow rate s o f les s tha n100,00 0 scf m (170,00 0 Nnw/hr'i . Th e 11s t o f potentia l applicabl e contro l technique s ca nthe nb e narrowe d furthe r dependin g o nth e capabilit y o f th e applicabl e contro l device , t o achiev e tn e require d performanc e levels . Fo r example , catalyti c incineratio nca nachiev e anexpecte d contro V efficienc y

o f greate r tha n95 % a t tota l volatil e organi c compoun d (VOC ) concentration s o f greate r tha n10 0 ppmv . Ver y

littl e dat a regardin g confo l devic e remova l efficienc y fo r specifi c HAP s ar e available . Therefore , withou t actua l sourc e tes t dat a fo r a specifi c emissio nstrea m an d contro l system , HA P remova l efficienc y I s generall y

assume d t o equa l tota l VO C remova l efficienc y (1) . CATALYTI C OXIDATIO N TECHNOLOG Y

Th e topi c o f thi s presentatio n1 s catalyti c Incineration , whic h1 s als o calle d catalyti c oxidatio nan d catalyti c destruction . Catalyti c Incineratio nP. 8



### 1 s a nai r pollutic ncontro l techniqu e whereby VOC s an

dvapor-phas e organi c ai r toxic s 1 na nai r emissio nstream ar e oxidize dwit htn e hel po f a catalyst . A catalys t 1 s a substanc e tha t accelerate s th e rat e o f a reactio nat a give n temperatur e withou t bein g appreciabl y change ddurin g th e reaction . Catalyst s typicall y

use dfo r VO C incineratio nInclud e platinu m an dpalladium . Othe r formulation s ar e als o used , Includin g meta l oxide s fo r emission s stream s con tainin g chlorinate dcompounds . A typica l catalyti c oxidatio nsystem wit hprimar y

an dsecondar y

hea t recover y 1 s show

n1nFigur e 1 . Proces s ai r emissions , generall y a t ambien t temperatures , ar e passe dthoug hth e primar y hea t exchange r t o recove r hea t fro m ho t exhaus t gases . I f necessary , th e emissio nstream 1 s the npreheate d t o catalyti c oxidatio ntemperature s 1na natural-gas-f1red , o r electri c pre heate r befor e passin g Int o th e catalys t bed . A smal l portio no f th e proces s ai r emission s 1 s separate dfro m the controlle dstrea nanduse da s combustio n ai r befor e primar y

hea t exchange . Th e catalys t be

d(o r matrix ) 1 s generall y a metal-mesh-mat , cerami c honeycomb , o r othe r cerami c matri xstructur e designe dt o maximiz e catalys t surfac e area . Catalyst s ma y als o b e 1nthe for

m o f sphere s o r pellet s whic h ma y operat e eithe. * 1 na T1"xe do r fluidize dbe dconfiguration . Car e mus t b e take ntha t highprehea t temperature s accompanie db y th e Increas e 1 ntempera tur e du e t o combustio nd o no t resul t 1 nhig hoperatin g temperature s Inth e catalys t bed . Thi s coul dcaus e th e catalys t bedt o overheat an deventuall y los e it s activity . Exhaust , gases the npas s throug hth e ho t sid e o f th e primar y hea t exchang er , givin g u

phea t t o th e Inle t stream . I f the economic s ar e favorable , secondar y

hea t recover y

1 s used . Recovere dhea t 1 s ofte nuse dfo r proces s hea t or , 1

nth e cas e o f printin g operations , fo r drye r makeu pai r preheating . I f the oxidize dstream s contai nchlori i .te dcompounds , causti c scrubbin g ma y b e require dbefor e th e exhaus t stream ca nb e emitte dt o the atmosphere . Th e performanc e o f a catalyti c Incinerato r 1 s affecte db y severa l factor s including : (a ) operatin g temperature , (b ) spac e velocit y (reciproca l o ' residenc e time) , (c ) VO C compositio nai dconcentration , (d ) catalys t proper ties , an d(e ) presenc e o f polsons/'nMbltor s inth e emissio nstream . I n catalyti c Incinerato r design , th e Importan t variable s ar e th e operatin g temperatur e at th e catalyst be dinle t an dxh e spac e velocity . The operatin g temperatur e fo r a particula r destructio nefficienc y 1 s dependen t onth e concentratio nan

dcompositio no f the VO C i nth e emissio nstream an dth e typ e o f catalyst used . Spac e velocit y

1 s define da s th e volumetri c flow rat e o f the combine d ga s strea

m (1.«. , emissio nstream + supplementa l fue l • combustio nair ) enterin g the .•ta'ys t beddivide db y th e volum e o f th e catalys t bed . A s such , spac e velocit y

als o depend s onthe typ e o f catalys t used . At a give n spac e velocity , increasin g th e operatin g temperatur e a t the Inle t o f th e catalys t bedIncrease s the destructio nefficiency . A t a give noperatin g temperature , a s spac e velocit y 1 s decrease d(I.e. , a s residenc e time i ntn e

### HEATE D AI R T O BUILDIN

G EXHAUS T T O ATMOSPHER E

SECONDARY HEA T EXCHANGE R AMBIEN T MAKEU P AI R

NATURAL 6A S

COMBUSTION

AI RBLCME R PREHEATE R OXIDIZE REXHAUS T 6A S

PRIMARY HEA T EXCHANGE R (70 1 EFFICIENCY ) .CATALYTI C SYSTEM FEE D

CATALYS T BE D

PROCES S FA

N FRO M EMISSIO N SOURC E

PREHEATBURNE R M/tKEU P AI R 

### (AFTER(2) 1 

# 1

Figur e 1 . Proces s flo w sketc h- catalyti c oxidatio nsystemP.1 0

catalys t bed increases) , destructio nefficienc y Increases . Catalyti c 1ncin er.tor s ca nachiev e overal l VO C destructio nefficiencie s u p t o abou t 98 % an

d HA P destructio nefficiencie s u p t o abou t 95 % wit hspac e velocitie s 1 n th e rang e 30,00 0 t o 100,00 0 ga s hourl y spac e velocit y

(GHSV ) (3,4,5) . However , th e greate r catalys t volume s and/o r highe r temperature s require d fo r hig h destructio nefficiencie s (i.e. , 99% ) ma y mak e catalyti c incineratio n uneconomical . Th e performanc e o f catalyti c incinerator s 1 s sensitiv e *.o pollutan t characteristic s an

d proces s conditions . Therefore , 1 nther e ntroductor y discussions , 1 t 1 s assume d tha t th e emissio nstrea m 1 s free , fro

m poisons / inhibitor s suc ha s phosphorus , lead , bismuth , arsenic , antimony , mercury, . Iro noxide , tin , zinc , sulfur , and halogens . I t 1 s als o assume d tha t th e fluctuation s 1 nproces s condition s (e.g. , change s i nVO C content ) ar e kep t t o a minimum

a s ar e liqui d o r soli d particle s tha t coul d deposi t onth e catalys t an d for m a coating , thereby reducin g th e catalyst' s activit y by preventin g contac t betwee nth e VOC s an d th e catalys t surface . Additionally , catalys t U f e 1 s limite d b

y therma l agin g and b y los s o f activ e site s b y erosion , attrition , an

d vaporization . Wit hprope r operatin g tenperature s an d adequat e temperatur e control , ther e processe s ar e normall y slow , an

d satisfactor y performanc e ca nb e maintaine d fo r 3 t o 5 year s befor e replacemen t o f th e catalys t 1 s necessary . Th e dat a necessar y

t o perform

desig ncalculation s consis t o f th e emissio n stream characteristic s liste d belo w an d o f th e HAP contro l leve l a s determine d b y th e applicabl e regulation s (1) . Thes e dat a are :

o Maximu

m Flow Rat e o Temperatur e o Hea t Conten t o Oxyge nConten t o Moistur e Conten t o Require d Destructio nEfficienc y 

### [scf m (Nm3/hr) ] [° F (°C) ] [Btu/sc f (kcal/Nm3) ] (% ) (% ) (% )
I f dilutio nai r i s adde d t o th e emissio nstrea m upo nexitin g th e process , tn e dat a tha t wil l b e use d inth e calculation s ar e th e resultin g characteris tic s afta r dilution . Ingeneral , catalyti c incineratio n1 s applie d t o dilut e emissio nstreams . I f emissio nstream s wit hhig hVO C concentration s [I.e. , hea t conten t abov e 1 0 Btu/sc f (8 9 kcal/Nm 3 ) fo r ai r • ' VO C mixtures ] ar e treate d b y catalyti c incineration , the y

ma y generat e enoug hh.a t upo ncombustio nt o deactivat e th e catalyst . Therefore , dilutio no f th e emissio nstream t o hea t content s o f les s tha n1 0 Btu/«c f wit hai r 1 s necessar y t o reduc e th e concentratio no f th e VOC s (1) . Tabl e 1 present s suggeste d value s an d limit s fo r th e desig nvariable s o f a fixe d be d catalyti c incinerato r system t o achiev e a give ndestructio n efficiency . Fo r specifi c applications , othe r temperature s an d spac e veloci tie s ma y

b e appropriat e dependin g o nth e typ e o f catalys t employe d and th eP.1 1

emissio nstream

characteristic s (I.e. , compositio nan d concentration) . Fo r example , th e temperatur e o f th e flu e ga s leavin g th e catalys t bed ma y b e lowe r tha n1,00 0 ° F (538 °C ) fo r emissio nstream s containin g easil y oxidize d compound s an

d stil l achiev e th e desire d destructio nefficiency . Not e tha t th e destructio nefficienc y fo r a give ncompound ma y vary dependin g o

nwhethe r th e compoun d 1 s th e onl y VO C 1 nth e emissio nstream , o r 1 t 1 s par t o f a mixtur e o f VOC s (3) .

Tabl e 1 . Catalyti c Incineratio nSystem Desig nVariable s (4,5,6 ) 

### Require d destructio n e/f1cienc y (t ) Hlnimu m

temperature a t th e catalys t be d Inle t [ 8 

### F(°C) ] Temperatur e a t th e catalys t be d outle t (Minimum-Maximum

) [°F( 8 

### C) ] Spac e velocit y (hr-1 )

9 0 60 0 (316 ) 1,000-1,20 0 (538-649 ) 40,00 0 9 5 60 0 (316 ) 1,000-1,200 - (538-649 ) 30,00 0

Supplementar y

fue l ! s adde d t o th e catalyti c incinerato r system t o provid e th e hea t necessar y t o brin g th e emissio nstrea m up t o th e require d catalyti c oxidatio ntemperatur e fo r th e desire d leve l o f destructio neffi ciency . Fo r a give nInle t temperature , th e quantit y o f supplementar y

hea t neede d i s provide d by : (a ) th e hea t supplie d fro m th e combustio no f supple mentar y fuel , (b ) th e sensibl e hea t containe d 1nth e emissio nstream a s i t enter s th . catalyti c incinerato r system , an d (c ) th e sensibl e hea t gaine d b y th a emissio nstream throug hhea t exchang e wit hho t flu e gases . I f recupera tiv e hea t exchang e i s no t practice d a t a facility, the nIte m (c ) wil l be zero . CAS E STUDY1 : AI RSTRIPPINGO F GROUNDWATE R

Ai r strippin g o f groundwate r ha s bee nshow nt o b e anefficien t an d cos t effectiv e metho d o f removin g VOC s fro m groundwate r an

d soil . Th e remova l o f dissolve d fue l fraction s an d chlorinate d solvent s a t efficiencie s 1 nexces s o f 95 % ha s bee ndemonstrate d onsevera l occasions . Unfortunately , thes e con taminant s ar e transferre d t o th e ai r wher e the y ma y continu e t o pos e a n environmenta l an

d healt hthreat . Regulatio no f suc hemission s ha s already considere d 1 nmany

state s Includin g Michiga nan d California . Th e appHca bHt y

o f catalyti c oxidatio nt o th e contro l o f groundwate rstrippin g gaseou s emission s wil l b e reviewe dwit hspecia l attentio ngive n t o syste m

design s andcas e histories . Th e variet y o f contaminant s an dcat alys t poison s encountere d1 nstrippin g operation s wil l ali o b e reviewed . Presently , few

option s ar e availabl e fo r th e contro l o f groundwate r ai r strippin g emissions . Vapor-phas e carbo nadsorptio nan dtherma l Incineratio n ar e th e tw o treatmen t method s whic har e bes t established . Thes e technologie s hav e som e disadvantages . Adsorptio nmerel y transfer s th e contaminan t t o a soli dphase , wnic h1 ntur nrequire s disposa l o r regeneration . Regeneratio n wit hsteam

result s i na contaminate dwast e wate r stream whic hrequire s treat men t an ddisposal . Therma l Incineratio nma y b e expensive , sinc e 1 t require s a substantia l energ y Inpu t t o destro y

dilut e gas-phas e contaminants . Cata lyti c oxidatio n1 s establishin g Itsel f a s a ne w alternativ e t o thes e mor e establishe dtechnologies . Lik e therma l Incineration , 1 t I s a nultimat e dispo sa l method , bu t sinc e 1 t operate s a t muc hlowe r temperatures , th e energ y cost s ar e als o lower .
A hypothetica l system wit hcatalyti c destructio no f ai r strippin g effluent s i s picture dI nFigur e 2 (7) . A1 r 1 s countercurrentl y contacte d wit ha contaminate dwate r stream . Mos t volatil e compound s ar e transferre dt o th e ai r stream , andth e wate r receive s a fina l cleanu pI nth e liqui dpolishin g ste pbefor e disposal . Th e catalyti c destructio no f organi c emission s inth e ai r strea m

differ s fro

m othe r catalyti c pollutio ncontro l application s i n severa l importan t aspects . First , th e concentratio no f th e contaminant s in th e ga s phas e i s quit e low , i nmos t case s les s tha n10 0 ppmv . Second , tn e humidit y

level s ar e unusuall y hig hsinc e th e ai r stream 1 s saturate dcomin g of f th e strippin g unit . Third , a wid e variet y o f contaminant s andmixture s rangin g fro

m chlorinate dcompound s an dsolubl e fue l fraction s t o pesticide s andpolychlorinate dbiphenyl s ma y b e i nany

groundwate r source . Finally , th e ai r stream

exitin g a groundwate r strippe r ma y hav e hig hconcentration s o f minera l aerosol s an dcatalys t poison s (e.g. , hydroge nsulfide ) tha t wil l shorte ncatalys t Ufe . Al l o f thes e factor s mak e th e desig nan dImplementa tio no f catalyti c treatmen t uncertain . Th e emission s fro

m ai r strippin g unit s ma y consis t o f a comple xmixtur e o f reactant s includin g bot hfue l andsolven t fractions . A typica l exampl e o f a nai r strippin g of f ga s stream 1 s show

n1 nTabl e 2 . Thi s tabl e list s th e concentratio no f selecte dcontaminant s emitte dfro m a pilo t ai r strippin g uni t a t Wurtsmit hAi r Forc e Bas e i nMich<ga n(8) . Here , n o individua l con taminan t exceed s 7 0 ppmv , bu t th e cumulativ e tota l exceed s 17 0 ppmv . Th e energ y

burde no f heatin g a cold , water-lade nai r strippin g effluen t stream shoul db e lowe r fo r a catalys t syste m tha nfo r therma l Incineration , bu t i t stil l represent s a considerabl e operatin g cost . Th e ai r fro m mos t ai r strippin g unit s ca nb e considere dt o b e saturate dwit hwate r (100 % relativ e humidity) . Thi s correspond s t o a nabsolut e wate r vapo r concentratio no f betwee n0. 8 an

d3.1 % I nth e exi t str.am . Th e actio no f bubble s 1 nth e strip pin g uni t als o produce s a larg e amoun t o f liqui daerosol . Th e carryove r o f liqui dwate r i nth e form o f small , droplet s an daeroso l represent s a naddi tiona l larg e hea t burde no nan y catalys t be dan

dshoul db e minimize db y th e us e o f demister s o r filter s i f possible . Aeroso l remova l ha s a nadditiona l0 0 GROUNDWATE R INLE TRIPPERKEDTOWERAIRST



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SUPPLEMENTA L FUEL ~ SCRUBBE R

CATALYS T BE D

^ PLENU M ^ " ^ CHAMBE R * ••* •rl» i •• •• ::::t::;t::: : l-jiijiiHit j !j!::ii::::i i 

# PlP i si::i::::t:: : SCRUBBE R

—*>E.FLUEN T

CATALYTI C INCINERATO R

•WATE R EFFLUEN T

LIQUI D POLISHIN G STE P



# Figur e 2 . Syste

m configuratio nfo r catalyti c destructio n o f ai r strippin g emissions .

T J E oP.1 4

advantage , i ntha t minera l o r biologica l matte r whic hmigh t fou l en d deacti vat e th e catalys t be d 1 s als o removed .

Tabl e 2 . Typica l Organi c Concentration s i n

Ai r Strippin g Overhea d (8 )

Compoun d Pentan e Cyclohexan e Methy l cyclopentan e 2,3-D1methy l butan e Trichloroethylen e Benzen e Ethy l benzen e Cumene Mixe d xylene s Tota l Concentratio n i n ga s phas e (ppmv) a 42. 4 66. 1 7. 7 1. 6 17. 9 9. 2 8. 3 3. 4 21. 3 177. 9

Calculate d a t a gas/liqu1 d rati o o f 42/ 1 fo r l-1n . (2.5-cm ) Pal l rings . Th e hig hconcentratio no f wate r vapo r 1 nth e emissio nstream represent s a majo r deferenc e betwee nthi s applicatio no f catalyti c contro l an d othe r mor e t^ica l applications . A s o f now , no fir m basi s exist s t o predic t th e behavio r o f non-halogenate d hydrocarbo noxidatio ni nth e presenc e o f water . Onth e othe r hand , th e effec t o f wate r o nth e catalyti c destructio no f chlorinate d compound s i s generall y though t to be beneficial . Th e mos t easil y treate d product s o f thi s proces s ar e hydrochlori c ad d (HCl) , carbo ndioxide , an d water ; however , some solvent s suc ha s trichloroethylen e (C2HCI 3 do no t hav e stoichiometri c amount s o f hydroge nto allo w complet e reactio no f th e chlorin e t o HCl . i'o r thos e compounds , wate r may serv e a s thi s hydroge n source , o r ma y

mere' y favorabl y

alte r th e reactio nthermodynamics . Othe r hydroge nsource s suc ha s methan e o r propan e ma y als o b e beneficia l 1 npromotin g HC l formation . A s wit hth e non-halogenate d hydrocarbons , a cleare r under standin g o f th e catalyti c chemistr y I s essentia l to understandin g th e rol e o f wate r vapor . A s a furthe r complication , many contaminate d groundwate r source s ma y con tai nmixture s o f hydrocarbon s an d halogenate d compounds . Laborator y an d pilo t studie s hav e found significan t mixtur e effect s fo r oxidatio no f hydro carbons , chiefly

1 nth e for

m o f Inhibitio n(9,10) . Thi s mean s tha t th e cata lyti c oxidatio no f a give ncompoun d I s generall y negativel y

Impacte d b

y th e presenc e o f mixtures , and highe r catalys t be d operatin g temperature s ma y b e necessar y

t o achiev e adequat e destruction . Informatio nonmixtur e effect s fo r halogenate d compound s 1 s extremel y limited .P.1 5

Catalyst s expose d t o th e ai r strippin g effluen t ar e subjec t t o deactiva tio nfro

m severa l sources : fouling , therma l degradation , polsoninq , an d catalys t volatilization . Th e catalys t bed ma y plug o r becom e encrusted , thereb y losin g It s effectivenes s du e t o dissolve d salt s an d minera l matte r 1 nth e ai r strippin g of f gases . A s mentione d previously , remova l o f aerosol s pric r t o th e catalys t uni t ma y alleviat e thi s problem . I f th e catalys t be d 1 s operate d a t hig htemperaturi- s [greate r tha n1,11 0 ° F (60 0 °C) ] fo r prolonge d periods , sinterin g o f activ e nobl e metal s ma y occu r als o resultin g i nlos s o f activity . Groundwate r als o ofte ncontain s significan t amount s o f readil y strlppanl e compounds , suc ha s hydroge nsulfid e (H2S) , tha t ma y poiso n-.h

e catalys t surfac e b

y adsorbin g an

d blockin g activ e sites . Highe r operatin g temperature s ma y

remov e som

e o f thes e poisons , bu t sinterin g ma y the nbecom e a problem . Finally , some reactants , especiall y halogenate d compounds , ma y chemicall y

bon d wit hth e activ e catalys t an d subsequentl y

volatiliz e fro

m th e surface . Th e los s o f catalys t associate d wit hthi s vaporizatio nproces s Inevitabl y

result s 1 nlowe r catalys t efficiency .
A recen t EPA

repor t (11 ) identifie d 17 7 ai r stripper s 1 nth e Unite d States . O f these , 1 7 ar e equippe d wit hai r emissio ncontrols . O f th e 1 7 facilities , 1 use s a catalyti c Incinerator , 2 hav e ope nflares , 2 hav e therma l Incinerators , and 1 2 hav e granula r activate d carbo nadsorbers . Installatio n o f th e ?.i

r contro l devic e wa s require d b y th e governin g stat e a t 9 o f thes e 1 7 sites . Th e catalyti c Incinerato r Identifie d 1 nReferenc e 1 1 1 s locate d a t th e U.S . Coas t Guar d Bas e I nTravers e City , Michigan . Thi s ai r strippe r system bega n operatio ni n1985 . Th e catalyti c Incinerato r wa s Include d 1 nth e Initia l desig nan

d installatio no f th e ai r strippin g system . Th e ai r strippe r In stalle d a t thi s sit e 1 s a rotary high-gravit y

ai r strippe r whic hachieve s hig hremova l efficiencie s a t lowe r ai r t o wate r ratio s tha npacke d towers . Th e lowe r ai r flow

fo r thi s typ e o f ai r strippe r result s i nhighe r pollutan t concentration s i nth e ai r strippe r exhaust . Th e catalyti c Incinerato r a t Travers e Cit y

wa s installe d fo r destructio no f benzene , toluene , an d xylen e strippe d fro

m th e groundwater . Th e catalyti c oxidatio nuni t 1 s designe d fo r a flo w o f ?,00 0 scf m

(3,40 0 Nm3/hr ) an

d operate s a t 50 0 t o 60 0 ° F (26 0 t o 32 0 °C) . Th e desig nefficienc y fo r thi s catalyti c Incinerato r wa s 90 % (11) . However , n o performanc e dat a ar e availabl e (12) . Th e estimate d Installe d cos t fo r th e catalyti c uni t i s $198,500 , an d annua l operatin g cost s fo r th e 2,00 0 scf m

(3,40 0 Nm3/hr ) uni t ar e $95,92 0 (base d o nthir d quarte r 198 6 data ) (11) . A catalyti c incinerato r ha s bee nbuil t fo r contro l o f organi c ai r emission s fro

m ai r strippin g o f groundwate r 1 ntwo additiona l cases . Th e U.S . Ai r Forc e ha s installe d a fluidize d bed , nonpreciou s meta l catalys t system fo r contro l o f trichloroethylen e an d 1, 2 dichloroethylen e ai r strippin g emission s a t Wurtsmlt hA1 r Forc e Bas e 1 nMichigan . Th e treate d ai r flow 1 s 1,10 0 scf m

(1,87 0 Nm3/hr ) a t anoperatin g temperatur e o f 90 0 ° F (4o 0 °C) . Withou t auxiliar y

equipment , i t 1 s reporte d tha t th e strippe r cos t $70,000 , whil e th e catalys t system cos t $126,000 . Catalys t lif e i s expecte d to b e 2



### 1 0year s wit hcatalys t agin g bein g th e resul t o f attritio no f th e catalys t pellets . Catalys t replacemen t cos t ha s bee nquote da t $1,200 . Performanc e dat a ar e no t ye t availabl e (12) . Th e destructio nperformanc e achieve ddurin g pilo t scal e testin g o f a n ai r strippe r exhaus t stream containin g benzen e an dtoluen e 1 s presente d graphicall y

I nFigur e 3 (13) . Th e locatio no f thes e test s wa s no t Identified . Th e Incomin g ai r fro m th e strippin g uni t containe dles s tha n1 0 ppm v tota l organics . CAS E STUDY2 : GRAPHI C ART S

Drye r emission s fro m th e graphi c art s (hea t se t we boffse t printing ) Industr y

ar e primaril y

compose do f hydrocarbo nsolvent , alcoho l (1 f used) , wate r vapor , an

dth e byproduct s o f burner combustio n(carbo ndioxid e an d trace s o f unburne dnatura l gas) . Eventuall y al l o f thes e material s ar e ex hauste dfro

m th e drye r resultin g i nthre e pollutio nproblem s whic hnee dt o b e addressed : "smoke " o r opacity , odor , an dVOCs . Th e "smoke " observe d1 s actuall y condensin g in

k solvent s andwate r vapor . Th e odo r 1 s a functio no f th e solvent s an

dresin s used . Tn e organi c compound s ar e th e hydrocarbo nsolvents , alcohol , andunburne dnatura l gas . A pollutio ncontro l devic e mus t dea l wit h al l thre e o f thes e problem s t o b e effective . Typica l In

k solvent s use d1 nth e we boffse t industr y ar e petroleum fraction s distille dfro m crud e oi l an

dar e simila r t o No . 2 fue l oil . Thes e solvent s typicall y

boi l i nth e rang e o f 44 0 t o 60 0 ° F (22 5 t o 31 5 8 C ) an dar e generall y

compose do f approximatel y 85 % aliphatic , 10 % aromatic , an d5 % olefini c hydrocarbons . Carbo nnumber s rang e fro m C 9 t o approximatel y C2 0 wit hth e larges t concentratio ni nth e are a o f C14 . A typica l molecula r weigh t fo r thes e solvent s i s 210 , an dthe y typicall y

hav e a ne t heatin g valu e o f 19,95 0 Btu/l b(11,08 0 kcal/kg) . Th e lowe r explosiv e limi t (LEL ) fo r a solven t o f thi s typ e i s approximatel y 0.455 % b

y volume a t 30 0 ° F (15 0 °C)(14) . A secon dcomponen t o f we boffse t drye r exhaus t 1 s ofte nIsopropy l alcohol . Use di nth e fountai nsolution , thi s ver y volatil e materia l i s carrie dwit hth e we bint o th e drye r wher e almos t al l 1 s evaporated . I t 1 s \iery difficul t t o measur e th e amoun t o f alcoho l whic hdoe s reac hth e drye r becaus e a percentag e o f th e alcoho l escape s int o th e pressroom a s fugitiv e emissions . Recen t advance s i nth e us e o f les s volatil e alcoho l substitute s hav e greatl y

reduce dth e volum e o f alcoho l use db y printin g plants . On e optio nfo r contro l o f we boffse t emission s 1 s catalyti c incinera tion . Catalyti c incinerator s ca nb e configure di nth e sam e manne r a s therma l incinerator s wit hth e us e o f primar y hea t exchanger s t o prehea t th e solvent lade nexhaus t t o th e temperatur e necessar y fo r catalyti c oxidation . I n addition , a secondar y hea t exchange r ca nb e adde da s I nFigur e 1 t o provid e heate dmakeu pai r t o th e dryer .



### 1 1

## 9 9



## £ 9 8
c to
U l 

### c o 

### o 

# s M 0 ) 

### O 

## 9 7

9 6 D Benzen e O Toluen e

95

. I 

# 1 175 20 0 22 5 25 0 27 5 Temperatrjr

e (°C ) 30 0 32 5

Figur e 3

. Destructlo t efficienc yo f a pilo t scal e catalyti c Incinerato r fo r

benzen e an d foluen e I n ai rstrippe rexhaust

.If , 1 nth e printin g process , bot hth e In k coverag e i s heav

y enoug han

d pres s spee d1 s highenough , the nth e catalys t prehea t burne r ma y b e abl e t o shu t off , allowin g th e uni t t o runwit honl y th e oxidatio no f In k solven t a s a sourc e o f energy . Thi s mod e o f operatio npresent s th e possibilit y fo r sub stantia l energ y

savings . Inaddition , whe nheate dmakeu pai r i s returne dt c th e dryer , th e nee dfo r fue l a t th e drye r i s reduced . Alternatively , 1 f th e heate d ai r 1 s use dt o driv e anothe r recover y devic e (absorptiv e chi^er , buildin g heatin g an dventilatin g system , etc.) , th e auxiliar y energ y require d t o fue l tha t devic e woul dals o b e reduced . Catalyti c incineratio ndoes , however , suffe r fro m a numbe r o f disadvan tage s i nthi s application . Heat-u ptime s ar e a s long fo r catalyti c unit s a s fo r therma l unit s du e t o th e larg e physica l mas s o f catalys t whic hmus t b e heate . t o th e prope r oxidatio ntemperature . Thi s disadvantag e ca nb e over com e t o some extent . B y incorporatin g anautomati c damper , th e syste m ca nb e maintaine di nth e "ready " mod e wlt na minimum energ y requirement . Th e cos t o f catalys t ca nb e substantia l causin g th e Initia l capita l Investmen t fo r a catalyti c system

t o b e fro

m 15 % t o 30 % highe r tha nfo r anequivalen t therma l system . Catalys t Uf e ma y var y fro m 1 t o 5 year s o r mor e dependin g o n th e compositio no f th e catalyst , a s wel t a s operatin g an dproces s variable s (14) . Inth e graphi c art s Industry , th e catalys t i ncatalyti c Incinerator s shoul db e monitore do na regula r basi s becaus e 1 t i s susceptibl e t o contamin atio nb y phosphoru s (phosphat e buffers ) fro m fountai nsolutions , silic a fro m silicon e gloss-enhance r sprays , o r chloride s fro m chlorinate dsolvent s o r blanke t was hsolutions . Th e preciou s meta l catalys t I s no t poisone db y sulfur , bu t bas e meta l catalyst s ar e rapidl y deactivate db

y sulfu r I nthi s typ e o f applicatio n(15) . Phosphoru s an

dsilic a accumulat e mos t rapidl y onth e leadin g edg e o f th e catalys t be dan

ddeactivat e th e catalys t b y maskin g th e preciou s metals . Bot hphosphoru s an

dsilic a bondt o eithe r th e alumin a substrat e o r alumin a washcoat . Becaus e o f phosphoru s an dsilic a poisoning , TE C Systems , a majo r supplie r t o th e printin g Industr y o f dryer s an

dancillar y

equipmen t Includin g catalyti c Incinerators , ha s gon e t o bea dtyp e catalys t bed s wit hlo w spac e velocitie s (abou t 7,00 0 t o 8,00 0 GHSV ) (15) . Wit hdeepe r catalys t beds , th e leadin g edg e o f th e catalys t tend s t o collec t th e poison s andthu s protect s th e catalys t bead s deepe r I nth e bed . Catalys t bed s wit hhig hspac e velocitie s (nea r 30,00 0 GHSV) , suc ha s monolit hcatalysts , ofte nrequir e frequen t clean ing , sometime s a s ofte na s ever y 3 months . Chlorid e poisonin g 1 s muc hles s commo ntha nphosphoru s o r silic a poison ing ; however , sinc e 1 t react s directl y wit hth e preciou s metals , chlorid e deactivate s th e catalys t a t muc hlowe r concentrations . Thre e potentia l source s o f chlorid e poisonin g ar e fir e extinguishin g systems , refrigeratio n system s whic hutiliz e fluorocarbon s suc ha s trlchlorotrlfluoroethane , an dchlorinate dhydrocarbo nsolvent s (15) . Insome cases , TE C System s ha s foun dtha t a catalys t uni t ma y fal l a complianc e tes t eve nthoug hth e catalys t i s i ngoo dshap e (15) . Failure s o f



### 1 3P.1 9



### thi s natur e hav e bee ntrace dt o cracke dhea t exchangers , lo w catalys t levels , abnormall y

low incineratio ntemperatures , leakin g bypas s dampers , an derron eou s testing .

CAS E HISTOR Y3 : FLEXOGRAPHI C PRINTINGPLAN T

A meta l oxid e catalys t I na fluidize dbe dconfiguratio nha s bee napplie d t o a flexographi c printin g plan t 1 nMassachusett s (2) . In•nan y ways , thi s us e 1 s simila r t o th e graphi c art s applicatio ndiscusse d1 nCas e 2 . Th e exhaus t fume s fro

m 1 0 flexographi c printin g dryin g oven s containin g 12 0 lb / h r (5 5 kg/hr ) o f VOC , 5 lb/h r (2. 3 kg/hr ) o f silicones , an dtrac e amount s o f chlorinate dhydrocarbon s ar e controlle dusin g catalyti c oxidation . However , sinc e th e catalys t surfac e 1 s continuall y renewe db

y abrasio n1nth e fluid ize dbed , th e problem o f maskin g th e catalys t surfac e wit hsilicone s i s avoided . Th e us e o f a meta l oxid e catalys t avoid s th e problem o f chlorin e poisoning . Massachusetts ' environmenta l emissio nregulation s requir e at leas t 95 % captur e o r destruction . Th e system

wa s Installe d1 nOctobe r 7.986 . Operatin g condition s ar e show ni nTabl e 3 , an

dar e typica l o f thos e use dfo r easil y combuste demis sions . Th e vendo r state s tha t th e teste defficienc y wa s 1nexces s o f 99% . Thi s hig hdestructio nefficienc y 1 s attribute dt o operatio na t 73 % o f desig n ai r flo w rate . Decrease dflow (henc e decrease dspac e velocity ) increase s destructio nefficiency . Th e plan t operate s 2 4 hrs/day , 5 days/wk , an d26 0 days/yr . Th e incineratio nsystem als o Include s a 70 % thermall y efficien t self-recuperativ e plat e typ e hea t exchange r fo r buildin g heating . Desig n condition s ar e show

no nth e flo

w sketc ho f Figur e 4 .
Tabl e 3 . Operatin g Condition s fo r Catalyti c Contro l o f a Flexographi c

Printin g Plan t (2 ) ~
Ai r Flow Rat e 11,00 0 scf m 18,70 0 Nm3/h r (Desig nValue ) 15,00 0 scf m 25,50 0 Nm3/h r VO C Loadin g 3 t o 6 % o f LE L (Fue l Value ) 1. 5 t o 3. 1 Btu/sc f 1 3 t o 2 8 kcal/Nm 3 Be dInle t Temperatur e 70 0 ° F 37 0 ' C Be dOutle t Temperatur e 77 5 t o 85 0 # 

### F 41 5 t o 45 5 ° C Catalys t Pressur e Dro p1 0 1n . wate r 18. 7 m m H g Fue l Consumptio n0.45 1 xlO^Btu/h r 114,00 0 kcal/h r

Th e cos t o f th e catalyti c incinerato r includin g th e catalys t an dproces s fanbu t no t Includin g th e cos t o f hea t exchanger s wa s $133,430 . Th e annua l operatin g cos t fo r fue l 1 s $14,071/y r a t anenerg y cos t o f $5.00/10 6 

### Bt u ($0.00002/kca1) . Thi s valu e doe s no t includ e an y credi t fo r buildin g heating cost * *hic hwer e cu t b y 50% . Catalys t cose s ar e $5,377/yr .



## 1 4

/HEATE D AI R T O BUILDIH O 

# t EXHAUS T T O ATMOSPHB €

SECONDAR Y HEA TEXCHANGE R AMBIENT MAKEU PAI R

PSEHEATE R

66 9 °F(35 4 °C

)
NATURA L 6A S OXIDIZE REXHAUS T SA d


### FfllHAfl Y HEA T EXCHANGE R r70 I EFFICIENCY ! CATALYTI C SYSTE M FEE D

COMBUSTIO N

AI RBLOWE R

PREHEA T BURNE RMAKEU P AI R EMISSIO N SOURC E

(AFTER(2) 1



## NATURAL GA S FUE L 1.01 0 Btu/sc f (8.99 0 kcal/N_3 ) 2 pil g (1 4 KPa ) 10.1 4 icf a (17.2 3 Na3/hr ) 0.615x10 6 Btu/h r (155.00 0 kcal/hr ) PflOCES S FA N S SYSTE M FEE D 15.00 0 «Cf

• 17. 97 2 Kf a 17 5 ° F 3. 1 Btu/ae f (2S.49 5 M3 )

(30
. 53 0 a3 ) (7 9 °C) (27. 6 kcal/N_3 )



## COMBUSTIO N

AI RBLOWE R OXIOIZE REXHAUS T GA S
68 8 ecf e 64 0 acf a 17 5 ° F (1.16 9 N»3/hr )

(1,42 7 _3/hr ) (7 9 °C) 13.01 0 stf a 24.16 0 atf a 37 7 ° F (23.50 0 Na? )

(41.05 0 t3 ) (19 2 °C ) 

# Figur e 4 . Catalyti c oxidatio nsystem - typica l operatin g conditions .

1 5P.2 1



### Th e vendo r als o calculate dcost s fo r a therma l Incinerato r operatin g at 11,00 0 scf m

(18,70 0 Nm3/hr ) wit hth e same hea t recovery . Fue l cost s wer e estimate da t *159,931/yea r a t $5.00/10 6 

### Bt u($0.00002/kcal) . Th e exi t tempera tur e o f th e incinerato r wa s estimate da s 1,40 0 ° F (76 0 8 

### C)(2) .

CAS E STUD Y4 : LATE XMONOME RPRODUCTIO N

Fo r man y years , on e o f th e accepte dmethod s o f oxidizin g gaseou s hydro carbo nemission s ha s bee nb y therma l incineration . Thi s becam e th e obviou s choic e whe ndealin g wit hcarcinogeni c chlorinate dhydrocarbo nemissions ; however , wit h2,20 0 ° F (1,20 0 °C ) oxidatio ntemperature s an d2-se c dwel l times , incinerator s became very larg e an

dth e fue l cost s excessive . Th e alternat e choic e wa s catalyti c oxidation ; however , th e catalys t wa s easil y po1<or:e dan dtn e uni t mad e Ineffective . AR I Technologie s ha s introduce da catalys t system

whic htna y

clai m ca ncomplet e th e reactio na t anaverag e be d temperatur e o f 70 0 ° F (37 0 °C ) whil e achievin g conversio nefficiencie s 1 n exces s o f 99.99 % (2) . On e difficul t applicatio no f chlorinate dhydrocarbo nemission s contro l 1 s th e manufactur e o f late xmonomers . Bein g a typica l batc hoperation , th e concentratio no f chlorinate dhydrocarbon s varie s widel y fro m a hea t conten t o f 4 t o ove r 30 0 Btu/sc f (3 6 t o 2,70 0 kcal/Nm3) , whic hresult s 1na poten tia l ttfliperatur

e ris e acros s th e catalys t o f 20 0 t o 1,50 0 ° F (9 5 t o 81 5 T) . Durin g period s o f very highconcentrations , th e temperatur e ris e acros s th e catalys t be di s kep t withi na reasonabl e rang e b y th e additio no f dilutio n air . At th e presen t time , fiv e plant s are operatin g successfull y usin g catalyti c Incineratio na s th e contro l technolog y o f choice . Th e rang e o f operatin g parameter s fo r a typica l 4,00 0 scf m (6,80 0 Nm^/hr ) catalyti c incineratio nsyste

m 1 s show

n1nTabl e 4 . Not e th e wid e rang e o f dilutio n ai r rate s neede dt o compensat e for tn e hea t conten t o f th e proces s ga s andth e nee dfc r causti c scrubbin g fo r contro l o f hydrochlori c ad d(HCl ) emissions . Th e hi t > conversio nefficienc y ma y be possible , I f th e chlorinate dhydro carbo nis viny l chloride , base donlaborator y result s whic hsee

m t o Indicat e tha t viny l chlorid e combustio ngoe s t o completio nbelow 70 0 ° F (37 0 °C)(16) .



## 1 6Tabl e 4 . Operatin g Condition , fo r Catalyti c Contro l o f Late xMonome r Productio nEmission s (2 )

( Chlorinate dH C Ga s Flow 5 0 t o 33 5 scf m 8 5 t o 57 0 Nm3/h r | Inle t Temperatur e 70 0 ° F 37 0 8 C [ Hea t Conten t 4. 4 t o 22 5 Btu/sc f 3 9 t o 2,00 0 kcal/Nn 3

Fue l Ga s Consumptio n0. 9 t o 3. 0 scf m 1. 5 t o 5. 1 Nm 3 /h r Dilutio nA1 r Flo w

6 0 t o 3,00 0 scf m 10 0 t o 5,10 0 Nn\3/h r Coolin g Wate r Rat e 11 0 t o 1,00 0 gp h41 5 t o 3,80 0 1/hr Causti c Additio nRat e 0 t o 15 0 gph0 t o 57 0 1/hr Wate r & Causti c t o Drai n6 5 t o 75 0 gp h25 0 t o 2,85 0 1/hr Stac k Temperatur e 9 5 t o 16 0 " F 3 5 t o 7 0 ° C Conversio nEfficienc y 99.999 %

Th e cos t o f a typica l 4,00 0 scf m (6,80 0 Km 3 /hr ) system Includin g th e majo r Item s o f equipmen t show n1 nFigur e 4 , *ate r an dcausti c manifolds , control s an

dcontro l panel , catalys t an dservic e platform s i s $350,00 0 t o $400,000 . Th e unit , whichI s preassemble d durin g fabrication , ca nb e in stalle di nth e fiel d1 napproximatel y 7 day s ?.

t anassembl y

cos t o f approxi matel y $25,000 . Th e operatin g cost s o f th e system ar e a functio no f th e chlorinate dhydrocarbo nconcentration s an d.h e Individua l plan t operatin g procedur e an

dca nonl y

b e calculate dbase dona specifi c applicatio n(2) .

CATALYTI C UNIT S FO

RCONTAMINAN T REMOVA L Ther e ar e severa l commercia l catalyti c unit s now onth e marke t inthi s country , an

dmany other s i nEurope . Hov/ever , t o ou r knowledge , ther e i s experienc e wit honl y thre e o f thes e i nconjunctio nwit hanai r strippin g unit . Mos t o f thes e unit s ar e no w use dfo r controllin g emission s fro m sol ven t strippin g operations , pain t spra y booths , an

dsimila r Industria l opera tion s wher e concentration s o f reactant s ar e muc hhighe r tha nai r strippin g emissions . Severa l o f th e commerciall y availabl e catalyti c Incinerator s hav e bee nidentifie d an

dar e describe dbelow : 1 . ARI : Thi s fluidize dbedcatalyti c Incinerato r wa s develope d1 nth e earl y 1970s . Develope djointl y b y Ai r Resources , Inc . (ARI ) an dHarsha w Chemica l Company , thi s technolog y ha s bee n1 ncommercia l us e sinc e 197 5 andI s bein g markete do c a turnke y basi s (16) . Th e catalys t 1 s a nonpreciou s meta l disposabl e pellet . Th e fluidize ddesig ni s especiall y goo d1 ntha t 1 t overcome s carbo nfoulin g (masking ) problems . Th e movin g catalys t be dallow s maske dcatalys t t o mov e t o highe r temperatur e zone s I nth e bed , thereby oxidizin g th e maskin g material . Othe r minera l deposit s (e.g . sulfur , phosphorus , silicon , salts ) whic hma y coa t th e surfac e ar e remove dfro m th e catalys t pelle t b y attritio n1 nth e fluidize dbed . Thi s result s i na catalys t lif e o f abou t 2 yocrs .



### 1 7P.2 3

Approximatel y

5 0 o f thes e fluidize d be d unit s ar e bein g use d fo r VO C control . O f th e 5 0 significan t portio nar e use d fo r contro l o f chlori nate d hydrocarbons . ARI an d Unio nCarbid e hav e recentl y cooperate d t o develo p a new system employin g AR I fluidize d be d catalys t technolog y an d Unio nCarbid e molecu la r siev e adsorben t expertise . Thei r system use s S1l1cal1t e adsorben t t o preconcentrat e organi c mission s befor e the y ar e fed t o th e catalyti c unit . Th e combine d system i s sai d t o be mor e cos t effectiv e tha ncata lyti c destructio nalon e sinc e th e catalyti c uni t ca nb e downscale d b y a facto r o f 1 0 o r mor e (2) . 2 . C E A1 r Preheater : C E market s bot htherma l an d catalyti c Incinerato r system s 1 nsize s rangin g fro m 2,00 0 t o ove r 100,00 0 scf m (3,40 0 t o 170,00 0 Nm3/hr) . Thei r catalyst , supplie d b y Johnson-Matthey , 1 s platinu m deposite d or a stalnles * stee l honeycomb . C E A1 r Preheate r ha s Installe d 1 7 catalyti c Indnera*; . -^ s a s o f 198 8 (17) . 3 . Deder t Corporation : Deder t market 1
.. . VTOX " catalyti c Incinerato r fo r Haldo r Topso e A/S , a Oanls hcompan y specializing incatalysts . It feature s a non-nobl e meta l catalys t resistan t t o chlorine , sulfur , an d phosphoru s compound s 1 nbot hmonolithi c an d pellete d forms . The y marke t a specia l "AOOX " uni t fo r lo w concentration s (les s tha n25 0 ppmv) , an d another , name d "REGENOX, " fo r "dirty " streams . Many o f thes e unit s ar e i nplac e fo r manufacturin g an d Industria l processes . 4 . Engelhar d (Torvex) : Sinc e th e earl y 1980s , thi s system ha s bee nmar kete d b y th e Engelhar d Corporation . Complet e system s ar e availabl e 1 n size s rangin g fro

m les s tha n1,00 0 t o 70,50 0 scf m (1,70 0 t o 120,00 0 Nm3/hr) . The' r catalyst s consis t o f preciou s meta l deposite d o n cerami c honeycombs . Betwee n197 6 an d 1988 , th e vendo r supplie d abou t 25 0 complet e catalyti c Incinerato r system s I nth e U.S . an d ove r 1,00 0 i nJapa nan

d ha s retrofitte d abou t 21 0 therma l incinerator s wit hcata lyst . 5 . Groundwate r Technology , Inc. : Groundwate r Technolog y provide s complet e groundwater cleanu p services . A s Such , they hav e entere d th e are a o f cleanu p o f ai r emission s fro m thes e operations . They repor t Instal latio no f thei r firs t catalyti c conversio nunit . Th e catalys t wa s obtaine d fro

m Johnson-Matthe y

an d consist s o f platinu m o na meta l sub strate . Effectiv e destructio no f fue l mixture s strippe d fro m ground wate r ha s bee ndt* d (13) . 6 . Johnson-Matthey : A majo r manufacture r o f catalyst s an d othe r material s employin g preciou s metal s market s a variet y o f sel f containe d catalys t treatmen t system s fo r remova l o f organi c compound s fro m gaseou s emis sions . Thei r "Honeycat " uni t ma y b e fitte d wit heithe r a cerami c o r meta l honeycom

bcatalys t tupport . Inexpensiv e unit s ar e markete d fo r treat t o f lo w volum e streams .



### 1 8P.2 4



### 7 .

8 . Met-Pr o Corporation : Formerl y Oxy-Catalyst , thi s compan y market s bot h therma l andcatalyti c Incineratio nsystem s andcarbo nadsorptio nsystems . The y emplo y a wid e rang e o f catalyst s Includin g bot hpreviou s an dnon preciou s metal s deposite do na monolithi c o r pellete dsupport . The y hav e installe dove r 20( 1 catalyti c incinerato r system s throughou t th e Unite dState s andsom e foreig ncountrie s (18) . TE C Systems : Thi s subsidiar y o f W.R . Grac e manufacture s an dmarket s catalyti c Incinerato r system s tha t utiliz e bot hgranula r andmonolithi c nobl e meta l catalyst s o nalumin a substrates . Thei r granula r catalys t 1 s manufacture db

y Davison . Thes e Incinerator s hav e bee neffectivel y use d t o contro l VO C emission s from a numbe r o f Industria l processes , primaril y i nth e printin g Industr y (15) . 

### 9 . Ultro x base d ogy . chlor l ai r ml Irrad i phase , pas s 1 tempe r Ultro xInternationa l continue s t o develo pan dmarke t a syste m ona combine dultraviole t (UV)/ozone/catalyt1 c oxidatio ntechnol " Whe nuse dfo r wate r treatment , th e nate dhydrocarbon s i s pumpe dInt o a xtur e 1 s bubble dthroug hth e wate:- . ate dwit hU

V light . I nadditio nt o a portio no f th e 'tydrocarbon s ar e nt o a U

V catalyti c reacto r wher e ature s slightl y

abov e ambient . groundwate r contaminate dwit h reactio ntank wher e anozone / Thi s bat h1 s simultaneousl y th e oxidatio ni nth e aqueou s strippe dfro

m th e wate r and furthe r oxidatio noccur s at

Ingeneral , a catalys t wit hhig hactivit y a t lo w temperature s 1 s desir able , hu t enoug hhea t mus t b e supplie dt o effec t complet e destruction . How ever , extremel y

hig htemperature s [greate r tha n1,38 0 " F (75 0 °C) ] ma y actu all y produc e additiona l partia l reactio nproducts . Basically , thi s mean s tha t a minimum

operatin g temperatur e o f a t leas t 66 0 ° F (35 0 9 C ) shoul db e employe dwit hcurrentl y availabl e catalysts . Mos t catalys t units , regardles s o f th e catalys t be dstructure , us e a preheatin g uni t t o attai nthes e tempera tures . Thi s preheate r ma y b e electri c o r anope nflame type . Th e ope nflame typ e i s generall y

powere db

y natura l ga s o r propane , an dma y accomplis ha significan t degre e o f destructio nb y Itsel f (10) . Thes e preheater s ar e use d wit hiiost o f th e reactor s now availabl e commercially , 1nbot hfixe dan d fluidize dbeddesigns . ECONOMIC S

Th e Contro l Technolog y Cente r (CTC ) repor t summarize s contro l cost s and efficiencie s fo r carbo nadsorptio na t fou r ai r strippe r site s (11) . I t the n complete s estimate s o f contro l cost s a t thes e site s fo r therma l Incineratio n an dcatalyti c oxidatio na t 98 % an d95 % efficiency , respectively .



### 1 9P.2 5



### Tabl e 5 summarize s thes e estimates . I t ma y b e notice dfro

m thi s tabl e tha t th e annualize dcost s o f contro l Increas e a s a functio no f ai r flow rat e fo r al l o f th e systems . Th e mos t rapi dIncreas e 1 ncos t 1 s fo r therma l incine ration , wit hcatalyti c oxidatio nbein g twic e a s cos t effectiv e fo r th e 19,20 0 s.-.f m (32,60 0 }tm3/hr ) unit . Thi s emphasize s th e energy saving s mentione d previousl y

fo r catalyti c systems . Carbo nadsorptionstil l ha s a mor e favor abl e operatin g cost ; however , fo r th e operatin g system s considere d1nth e CT C report , th e expecte dcontro l eff1c1.nv.1e s fo r therma l an dcatalyti c Incinera tio n(mor e tha n95% ) wer e muc hgreate r tha nth e observe defficiencie s fo r adsorptio n(7 0 t o 90%) . O f course , carbo nadsorptionca nattai nhighe r contro l efficiencie s wit hincrease dbe dsiz e o r decrease drelativ e humidit y o f th e emissio nstream . However , suc hchange s wil l resul t 1nIncrease d capita l andannualize doperatin g costs . A cos t analysi s fo r anexistin g hig h efficienc y

(greate r tha n95% ) carbo nadsorptio nsyste m 1 s no t presentl y available . Th e tradeoff s betwee ncontro l efficienc y an dcost s mus t b e mad e i nligh t o f th e seriousnes s o f th e contaminatio nthreat .



## 2 0Tabl e 5 . Summar y of Ai r Struttin

g Exhaus t Contro l Systea s (11 ) Sit e A Sit e B Verona Nel l fiel d Plainfiel d Conteainant s Concentration (ppbw ) Trichloroethylene (4.000 ) Trichloroethane (300 ) Chlorofor * (1.500 )

Wate r FloHrat a (gpa) * Ai r Flow-at e (scfa) *
Reaova l efficiency (% )
Contro l OctIons : 1.40 0
0.00 0
9 9

Carbon Adsorptio

n Contro l efficiency (* ) -e o Installe

d cos t (S ) 150.00 0 Oirec t operatin

g cos t (S ) 50.40 0 Tota l annualized cost s ($ ) 96.40 0
Tneraa l Incineratio n Contro l efficiency (% ) 9 8 Installe

d cos t (S ) 318.00 0 Oirec t operating cos t (S ) 432.00 0 Tota l annualized cost s (8 ) 492.00 0 Catalyti c oxidation Contro l efficiency (* ) 9 5 Installe

d cos t (8 ) 307.00 0 Oirec t operati.v j cos t (8 ) 210.00 0 Tota l annualized cost s (8 ) 269.00 0 15 5
1.30 0
99. 9

no t reported 152.00 0 31.30 0 77.80 0

9 8 187.00 0 86.80 0 129.00 0

9 5 135.00 0 51.60 0 86.10 0 Ethylen e dichlorid e



### (5 ) Trichloroethan e (12 ) 0 i ch1oroethylen e (10 ) Trichloroethylen e 

### (1 ) Perchloroethylen a (10 ) 1.90 0 5.50 0 99. 9 Perchloroethylen e (200 )

3.60 0 IV.20 0 9J. 6

7 4 223.00 0 62.70 0 124.00 0

9 8 285.00 0 303.00 0 358.00 0

9 5 251.00 0 150.00 0 201.00 0 9 0 500.00 0 120.00 0 221.40 0

9 8 432.00 0 1.047.00 0 1.123.00 0

9 5 586.on e 508.00 0 606.00 0
1 gp a • 3.78 5 liter/ainut e 9 1 scf a • 1.69 9 N* 3 /h rP.2 7

SUMMARYANO CONCLUSION S
Catalyti c oxidatio ni s a nai r pollutio ncontro l techniqu e whereb y VOC s an dgas-phas e organi c ai r toxic s ar e oxidize da t destructio n efficiencie s o f greate r tha n95% . Th e presenc e o f th e catalys t acceler ate s th e rat e o f oxidatio na t a give ntemperature . Thi s allow s combustio n a t lowe r temperature s tha nar e possibl e I ntherma l Incinerators . Cata lyst s ca nb e eithe r nobl e o r non-nobl e metal s deposite doneithe r pellete d o r monolithi c support s compose do f eithe r cerami c o r metal . Fixe dan d fluidize dbe dcatalys t system s ar e available . Th e mos t Importan t factor s affectin g performanc e ar e operatin g temperature , spac e velocit y (recipro ca l o f residenc e time) , contaminan t concentratio nandcomposition , cata lys t properties , andth e presenc e o f catalys t poison s or Inhibitor s 1 nth e emission s stream . Th e economic s o f catalyti c oxidatio r ca ngenerall y b e enhance db

y th e us e o f primar y hea t recover y

t o supplemen t andsometime s replac e electri c o r ga s preheatin g o f th e emission s stream befor e i t i s fe dt o th e catalys t bed . Secondar y hea t recover y

fo r ethe r proces s use s ca nals o improv e system economics . Catalyti c technolog y ha s had'timite

d applicatio nt o tn e contro l o f groundwate r strippin g emission s i nth e field . Th e know , barrier s t o it s applicatio nar e th e dilut e natur e o f ai r emission s fro nstrippers , th e hig hhumidit y

conten t o f th e ai r stream , th e comple xchemica l natur e o f th e emissions , th e nee dt o contro l chlorinate dcompounds , m d th e presenc e o f catalys t poison s andinhibitor s suc ha s hydroo' nsulfide , biologica l organi c matter , an

dminera l salts . Limite ddat a fro m tn e thre e know

n installation s ar e available . Th e printin g andgraphi c art s Industrie s mak e grea t _. e o f catalyti c oxidatio nfo r contro l o f thei r ai r emissions . Two application s o f cata lyti c technolog y

ar e discussed . I nbot hcases , th e vendo r claim s hig h destructio nefficienc y (greate r tha n95% ) a t moderat e Inle t temperature s [70 0 ° F (37 0 °C) ] du e t o th e eas e o f combustin nth e emissions . Bot h vendor s identif y

th e presenc e o f phosphorus , silicon , sulfur , andhalogen s i nth e exhaus t stream a s potentia l Inhibitor s o f catalys t effectiveness . Th e supplie r o f th e granula r fixe dbe dhobl e meta l o nalumin a catalys t syste m i s concerne dprimaril y abou t maskin g fro m phosphoru s an

dr.lllcon , andabou t deactivatio nfro m th e halogens . Th e supplie r o f th e # luid1ze d be dnon-nobl e meta l oxid e catalys t recognize s th e potentia l fo r masking , bu t 1 s no t concerne dsinc e th e surfac e o f thei r catalys t pelle t i s be lieve dt o b e continuall y cleane dI nth e fluidize dbed . I naddition , the y ar e apparentl y

no t concerne dabou t th e deactivatio no f non-nobl e meta l catalyst s b

y halogens . Severa l cause s o f low destructio nefficienc y othe r tha ncatalys t deactivatio nar e Identified : low operatin g tempera ture s an

dcatalys t levels , andth e bypassin g o f th e catalyti c uni t vi a cracke dhea t exchanger s an dleakin g bypas s dampers .



### 22.*$•'* •'• »-'".'«W»r . -»5^,--..> . „ — P ?f l



### On e vendo r ha s provide dInformatio nabou t the us e o f a fluidize d be dmeta l oxid e catalys t system fo r destructio no f chlorinate dhydro carbo nemission s a t fiv e sites . The y clai m a very highdestructio n efficienc y

(greate r tha n99% ) a t moderat e temperature s [70 0 ° F (37 0 °C)] . O f particula r interes t I nthi s applicatio n1 s th e hig hvariabilit y o f organi c emissio nrate s an dth e nee dt o ad

ddilutio nai r t o th e emissio n stream t o avoi doverheatin g o f th e catalys t bed . Th e nee dfo r scrubbin g o f hydrochlori c ad d(HCl)fro m th e catalyti c incinerato r exhaus t i s als o o f note . Nin e catalyst systwn * fn r contaminan t remova l hav e bee nIdentified . Mos t o f thes e unit s are now use dfo r controllin g emission s fro m solven t strippin g operations , pain t spray booths , an

dsimila r industria l opera tions wher e th e concentratio no f reactant s rang e fro m 25 0 t o 1,50 0 ppm v o r highe r a s limite db y 25 % o f th e lowe r explosiv e limi t (LEL) . Bot hnobi e meta l catalyt s an dnon-nobl e meta l oxid e catalyst s ar e represented . Thes e us e bot hpellete dcerami c an dmonolithi c (honeycomb ) cerami c o r meta l supports . Pellete dcatalyst s ar e 1 nuse 1 nbot hfixe d an dfluidize dbeds . Finally , th e economic s o f thre e contro l technologie s are evaluate d fo r groundwate r strippin g gaseou s emissions . Existin g dat a fo r carbo n adsorptio napplication s ar e compare dto . estimate s fo r the combustio n technologies . Carbo nadsorptio nha s a mor e favorabl e annualize dcost ; however , th e expecte dcontro l efficiencie s fo r therma l an dcatalyti c incineratio n(highe r tha n95% ) wer e muc hgreate r tha nth e observe d efficiencie s fo r adsorptio n(7 0 t o 90%) . Cos t analyse s fo r a nexistin g highefficienc y

carbo nadsorptio nsyste m ar e no t presentl y

available .



## 2 3

\/ REFERENCE S

1 U.S
. EPA
. "Handbook : Contro l Technologie s fo r Hazardou s A1 r Pollu tants. " EPA-625/6-86/014
. Septembe r 1986
. 2 Telefa x fro m Dowd , E
. J. , AR I Technologies , Palatine , Illinois , t o Kosusko , M. , U.S
. EPA
. Februar y 22 , 1988
. 3 U.S
. EPA
. "Parametri c Evaluatio n o f VOC/HA P Destructio n Vi a Catalyti c Incineration. " EPA-600/2-85-04 1 (NTI S PB85-19U87)
. Apri l 1985
. 4 U.S
. EPA
. "Contro l o f Volatil e Organi c Emission s fro m Existin g Station ar y Source s —Volum e 1 : Contro l Method s fo r Surfac e Coatin g Opera tions. " EPA-450/2-76-02 8 (NTI S PB260386)
. November 1976
. 5 U.S
. EPA
. "Guidelin e Series
. Contro l o f Volatil e Organi c Compoun d Emission s From Manufactur e o f H1gh-Dens1ty Polyethylene , Polypropylene , an d Polystyren e Resins. " EPA-450/3-83-00 8 (NTI S PB84-134600)
. November 1983
. 6 U.S
. EPA
. "Organi c Chemica l Manufacturing
. Volume 4 : Combustio n Contro l Devices. " EPA-450/3-80-02 6 (NTI S PB81-220535)
. Decembe r 1980
. 7 Vosusko , M. , M.E
. Mullins , K
. Ramanathan , an d T.N
. Rogers , "Catalyti c oxidatio n o f groundwate r strippin g emissions, " Environmenta l Progress , t o b e published
. 8 Stallings , R.L. , T.N
. Rogers , an d M.E
. Mullins , "Ai r strippin g o f volafl e organi c compound s fro m groun d water, " Journa l o f Environmenta l Science s 28 (3) , 1985
. 9 Gangwal , S.K. , M.E
. Mullins , J.J
. Spivey , an d P.R
. Caffrey , "Kinetic s an d selectivit y o f dee p catalyti c oxidation, " Applie d Catalysi s 36 , 

### 1988

. 1 0 Tichenor , B.A. , an d M.A . Palazzolo , "Destructio no f VO C vi a catalyti c incineration, " Environmenta l Progres s 6 (3) , 1987 . 1 1 U.S . EPA . "Ai r Strippin g o f Contaminate d Wate r Source s - A1 r Emission s an d Controls. " EPA-450/3-87-01 7 (NTI S PB88-106166) . Augus t 19tf7 .

y 1 2 Telecommunication . Ashworth , R.A. , U.S . A1 r Forc e Engineerin g & Service s Center , wit hKosusko , M. , U.S . EPA . Marc h1 , 1988 . 1 3 Telecommunication . Miller , P. , Groundwate r Technology , wit hVancll , M.A. , Radia nCorporation . Apri l 21 , 1987 . 1 4 TE C System s Divisio no f W.R . Grac e 4 Co . "A1 r Pollutio nContro l i n th e Heatse t We bOffse t Printin g Industry. " Repor t 8403 . Undated .



### 24

/

### 1 5 Lette r fro m Carman , R.A. , TE C Systems , D e Pere , Wisconsin , t o Kosusko , M. , U.S . EPA . Februar y 18 , 1988 . 1 6 Hardison , L.C , an dE.J . Oowd , "Emissio nccntro l vi a fluidize d be doxidation, " Chemica l Engineerin g Progres s 73 , 1977 . 1 7 Telecommunication . Bump , 0. , C E Ai r Preheater , wit hKosusko , M. , U.S . EPA . Februar y 23 , 1988 . 1 8 Kenson , R. , "Contro l o f volatil e organi c emissions. " Met-Pr o Bulleti n#1015 , serie s 1000 . 1981 .



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